<form action="php/libreria/Controlador/ControladorPrincipal.php" id="loginform" method="post">
    <table align="right">
        <tr>
            <td align="right">Usuario: </td>
            <td><input class="validate[required]" id="userLogin" name="userLogin" type="text" tabindex="1" /></td>
        </tr>
        <tr>
            <td align="right">Contrase&ntilde;a: </td>
            <td><input class="validate[required]" id="passwordLogin" name="passwordLogin"type="password" tabindex="2" /></td>
        </tr><tr>
            <td><input type="submit" tabindex="3" /></td>
            <td><input type="button" onclick="irRegistro()" value="Registrarse"></td>
        </tr>
    </table>
</form>